Means for producing a sweep wave optical picture with a cathode ray tube



Jul! "125,-".1199f BQJ, HAsKlNs ET Al. 2,137,177 mmuseras'aopucme A swEEP wAvE OPTICAL. PICTURE wrm A cmnon RAY TUBE 7 Filed De. 4, 1936 Patented July 25, 1939 mums ron. raonncmo a wave omen. morons wrrn a carnona mirl Butler .1. Haskins, Chicago, and. Henry Walter Mitchell, Wallkmll. lll

miam t The rotter Company, a corporation of Delaware 'i Application December 4, 1936, Serial No. 114,198

2 Claims.

This invention relates to means for producing a sweep wave optical picture with a cathode ray tube for investigating and measuring 4electrical or physical qualities' of a device under test.

Heretofore, the cathode ray tube has been employed in various ways to trace an electron stream upon a iluorescent coating applied to the end or walls of the tube and in order to investigate and y measure the same, costly and elaborate methods were employed, and errors introduced due to wire capacity and other stray currents involving expensive shieldings, and the mechanism was at no time inherently accurate.

Investigation of electrical phenomena, such as wave forms, voltage and current with a cathode ray tube requires that some means be provided whereby the electron stream placed under the influence of the phenomena, in order to be observed or studied, be caused to sweep across a screen in accordance with a predetermined time base.

It is a primary object of the present invention to provide a means whereby the above objections referred to are overcome and wherein the electron stream of the cathode ray tube-may be accurately investigated and measured to determine the variations and amplitude in respect to time of the electrical or physical qualities of a device under test.

A further object is to provide means for carrying a cathode ray tube in a path while connected with a device to be tested, for producing a sweep wave optical picture of the electrical or physical qualities of the device.

And a'further object is to provide a transparent scale through which the stream of electrons produced on the iluorescent coating o f the cathode ray tube is clearly visible for ascertaining the electrical or physical qualities of a device under test.

And a still further object is the` provision of a scale in the path of movement of the cathode ray tube which scale serves to indicate to the observer, the qualities of the device under test in accordance with a predetermined time base.

In the drawing:

Figure 1 is a view in side elevation of anapparatus illustrating a means for mounting a cathode ray tube in accordance with our invention.

Figure 2 is an end view of a cathode ray tube,`

illustrating a stream of electrons traced on the uorescent endthereof, while the tube remains stationary.

Figure 3 is an end view of a cathode ray tube, illustrating a. stream of electrons traced on the (CI. IVI-) fluorescent end thereof, while the tube remains stationary and a variation in the electron stream Figure 4 is a face view of a scale, illustrating the sweep wave optical picture produced thereon whiletie cathode ray tube is moved in a' path.

Figure 5 is an end view of a pair of cathode ray tubes arranged in superposed relation, wherein one tube projects its electron stream for amplitude and the other, for time; and

y Figure 6 is a face view of a scale employed with the pair o! cathode ray tubes shown in Fig. 5.

The apparatus shown 'comprises a base Ill on which a vertical spindle II is carried in a journal I2. The spindle II carries an arm I3 and a plurality 'oi rings I4, which are arranged in spaced relation thereon and which rings each contact a brush I5 carried in an upright member of insulation material I6 that is secured to the base I0. A motor I1 is also carried on the base I0 and is provided with a pulley I8 which has a belt I9 therearound that extends to a pulley 2li ilxed to the spindle II.y This motor i1 has leads Ila and |1b which may be connected to a source of power, and the motor may be oi any suitable type, but is preferably of the constant speed type for driving the spindle I I to drive the arm I3 at a constant rate of speed. A cathode ray tube 2l is secured to the arm I3 and is adapted to be driven therewith under-the control of the motor, 'and this cathode ray tube is connected through the rings Il and brushes I5 to a conventional form of oscillograph circuit, designated as a whole aaA.

As a conventional form of circuit is shown, it is thought that ai.4 brief explanation of the wiring connections will suillce for a thorough understanding oi its application with the device. The circuit A has terminals 22-23 for the heater supply of the element 24 and terminals 25-26 from the rectifier for the anode 21 and grid l18,'while the terminals 25J-III and 3I-32 are for connecting the device under test to the pairs of plates 33-34 and 35-38, respectively, of the cathode ray tube 2 I. A

During the operation of the apparatus with the cathode ray tube 2| in position on the arm I3 and with a device under test connected with the circuit A,a stream of electronsistraced on the fluorescent end 31 of the cathode ray. tube. As the apparatus is rotated at a constant rate of speed `by the motor I1. the tube is carried therewith and the stream of electrons traced on the iluorescent end 31 of the tube will appear visible to the eye as a sweep wave optical picture, and u readily detected.

` In order toaccurately trace and measure the sweep wave produced by the cathode ray tube during the operation of the device, a scale 38 is provided. This scale Il is supported on a frame I9 secured -to ,.thebase il and supports the scale .3l in proper alignment with the cathode ray tube 1I; 1This scale 3l may be of any transparent material through which the stream oi electrons traced on the nuorescent lend Il 'of the cathode" `ray tube will be visible, and the amplitude and time may be accurately measured.

As the tube 2| is driven ,at a constant rate of speed, through 360 degrees, the stream of electrons traced on the iluorescent end Il of the tube will be visible with each cycle oi' operation of the apparatus, or in other words, the sweep wave optical picture will be repeated many times during the test. In this manner it is* possible to accurately measure the amplitude and time of the qualities of the device under test, and a greater flexibility of measurements are made possible by the use of a cathode ray tube. This type of tube provided with time axis and detlection, electrodes, produces a picture of the phenomena being studied on the iluorescent end wall of the tube, which picture is spread out and rapidly repeated on the` scale plate to facilitate the study and analysis of the device under test. In Figure 4, is shown a type ot scale employed `in connection with the apparatus. This. scale has g'raduations thereon arranged in accordance with the amplitude and a predetermined time base, the scales being interchangeable to conform with the type of device under test.

While the apparatus remains stationary and a stream of electrons are traced on the fluorescent end 31 of the cathode ray tube 2| with slight variations of the electrical or physical qualitiesv this instance, the tube Il is arranged to trace a stream of electrons for amplitude on the uoreseent end lla thereof, while the tube Il is arranged. to trace a stream of electrons for time base on the iiuorescent end Ila thereof, the scale 'circuits may be employed in which a device under test may be connected with a cathode ray tube that is adapted to move in a path and also other means of connecting the circuit with the tube may be employed, as our invention relates particularly to the means for supporting and moving a cathode ray tube in a path to produce a sweep wave optical picture and to trace a stream oi electrons on the iiuorescent end thereof with a scale positioned for accurately investigating and measuring the amplitude and time oi' the qualities of the deviceunder test.

We claim:

l. An apparatus for producing a sweep wave optical picture of the electrical and physical qualitiesjof a device under test comprising the combination of a cathode ray tube, means for bodily revolving said tube at a constant rate of speed, a circuit for the tube for producing a stream oi electrons against the end 0i said tube and for deflecting said stream in response to the electrical and physical -qualities of the device under test, and a viewing screen having a, scale thereon and through which screen the deflected electron stream is visible.

2. An apparatus for measuring the electrical and physical qualities of a device under test comprising the combination of a cathode ray tube, means for revolving said tube through 360`at a constant rate of speed, a circuit for the tube and to connect the device under test for producing and defiecting a stream of electrons against the end of said ltube in response to the electrical and physical qualities of the device, and a transparent scale through which the deflected streamof electrons is visible to-be measured. 

